Locally, the East End has become synonymous with wine and winemaking, but beyond the towering buildings of New York City, Long Island is known about as well for its wineries as it is for its part in putting a man on the moon.

On a sparklingly clear, cold day last week, a delegation from the Champagne region of France was getting a jump on New Year’s eve by toasting with some North Fork bubbly. In the brand new tasting room of Southold’s Sparkling ...